Tunneling shield



G W. RUSSELL TUNNELING SHIELD Dec. 1938.

3 Sheets-Sheet 1 Filed Sept. 26, 1936 In verz for,

Dec. 6, 1938. G w RUSSELL 2,13%,563

TUNNELING SHIELD Filed Sept 26, 1956 s Sheets-Sheet 2 1?? veh?or1 il a , 11938. a. w. RUSSELL TUNNEL ING SHIELD Filed Sept. 26, 1936 3 Sheets-Sheet 3 M0WE02 Patented Dec. 6, 1938 UNITED STATES 2,139,563 YTUNNELING SHIELD Gordon W. Russell, Needham, Mass., assignor to James Russell Boiler Works Company, Boston, Mass, a corporation of Massachusetts Application September 26, 1936, Serial No. 102,712

12 Claims.

This invention relates to tunneling and to tunneling heads or shields.

In tunneling it is customary to employ a shield which supports the side walls of the tunnel between the forward end of the tunnel and the tunnel lining within which shield the excavators operate.

The shield is provided with hydraulic jacks which bear upon the end of the lining, or the equivalent, to advance the shield forwardly as the work of excavation progresses. a

The hydraulic jacks are supplied with operating fluid under relatively great pressure, sometimes as much as 5000 pounds per square inch. The hydraulic fluid at such pressure is provided by a motor operated pump. It is quite common practice to locate the pump and its motor on the surface at the entrance to the tunnel and to transmit the hydraulic fluid under pressure through a pipe line to the shield at the head of the tunnel. In some instances, with long tunnels, the pump may be a mile or so from the shield and hence the hydraulic fluid under high pressure has to be transmitted through a pipe line of the same length. The loss of hydraulic pressure in the long pipe line is very great, as much, for instance, as half the total pressure. Furthermore, a long pipe has many joints therein at which leakage can occur. While the leakage paths may be in themselves small the aggregate is large and at the extreme high pressure employed the amount of hydraulic fluid lost by leakage can be very great.

It has been proposed, also, to place the pump and its motor in the tunnel near the head. Such a position of the pump is highly objectionable, however, since it greatly interferes with the movements of the workers and material and also-requires that the pump and driving motor be portable and have a detachable and flexible driving connection with the shield.

To overcome these difficulties it is an object of the present invention to provide a tunneling shield and the hydraulic pump and its motor and the jacks as a unitary apparatus, the pump and motor being carried by and located in a part of the shield where it is out of the way of traflic. With this arrangement the piping between the pump and the jacks is short so that pressure and leakage losses are insignificant. The hydraulic piping is permanent and need not be disconnected and reconnected periodically as has been necessary heretofore. The pump and motor are out of the way so that passage along the shield and the tunnel is not obstructed. The pump by reason of practical absence of leakage and pressure losses can berelatively small and compact and consume materially less power.

By having the pump carried by the shield it is practical to employ oil as the hydraulic fluid and since there is substantially no loss of fluid and the amount required for the operation of the system is small it is also an object of the invention to provide the'shieldiwith a storage tank for the oil, and particularly to locate the tanks between the outer and inner shells of the shield and between the reinforcing ribs or partitions.

By having the hydraulic pump and its motor carried by the shield the pressure of the hydraulic fluid acting on the jacks can be readily varied to adjust the rate of advance of the shield to variable conditions of soil encountered from time to time during the advance of the tunnel; and means for accomplishing such result is a further object. of the invention.

A further object of the invention is an improved arrangement of pump, jacks and hydraulic circuit therefor, all carried by the shield, whereby the operation of all of the jacks or any one of them can be selectively controlled from a common operating station.

' The advancing shield often has a tendency to rotate in advancing'through the soil, which is undesirable as it would result in throwing the pump into an undesirable and perhaps inoperative position. Hence an object of the present inventionis the provision of a shield having a jack which can be inclined on one side or another of a mid position where it is parallelwith the axis of the shield for the purpose of exerting a rotary thrust on the shield in a direction to offset the tendency of the shield to rotate.

A further object of the invention is the provi- ,sion of hydraulic jacks of which the direction of thrust on the shield can be changed so as to offset any tendency of the shield to move in an unwanted direction and to cause the shield to advance in the desired direction.

A further object is generally to improve the construction and operation of tunneling shields.

Fig. 1 is a section of a tunneling shield embodying the present invention, taken through the longitudinal axis thereof.

Fig. 2 is a section taken along line 2-2 of Fig. 1.

, Fig. 3 is a section taken along line 3-3 of Fig. 1.

Fig. 4 is a detail of one of the jack openings in the rear diaphragm of the shield.

Fig. 5 is a section taken along line 5--5 of Fig. 3 and illustrating one of the jacks.

Fig. 6 is a diagram of the hydraulic system.

The tunneling shield herein shown to illustrate the invention comprises an outer cylindrical shell H] of suitable length and diameter having in the interior thereof the rear diaphragm l2 and, spaced forwardly therefrom, the front diaphragm M. The diaphragms consist of circular plates welded or otherwise attached to the shell and having central openings 16 and I8, respectively, through which access to the front and rear parts of the shield is provided. Ribs or partition plates 20' are angularly spaced about the inner circumference of the shell and are located between the diaphragms and are welded to the diaphragms and the shell.

The forward portion of the tunnel is provided with an inner conically shaped shell 22 which extends from the forward edge 24 of the shell, where it is welded or united thereto, to the opening l8 of the front diaphragm where it is welded to said diaphragm. Alternate short ribs or partition plates 26 and long ribs or partition plates 28 are disposed between the outer and inner walls l0 and 22 of the shield and are angularly spaced thereabout and are welded to both walls and also to the front diaphragm. This arrangement provides a strong structure adapted to resist external pressures and also to receive the thrust of the jacks. A floor plate 29 extends between and lies in the bottom parts of the diaphragm openings and is aflixed to both diaphragms.

The shield is provided with a plurality of jacks each comprising a cylinder 30 having a piston therein connected to a piston rod 32 which projects forwardly of the rear end of the jack and is provided with a head 34. A pressure retaining gland 35 surrounds the outer end of the piston rod and is drawn against the rear end of the cylinder. Thehead 34 of the piston rod bears against a shoe 38 and is connected thereto through a loose pivotal connection 40. The front end of the jack is seated in a cup shaped thrust bearing member 42 or other support which is secured to the front diaphragm l4 and which permits a limited, although suflicient, amount of angular adjustment of the jack.

The jacks are distributed between the partition walls 20. The thrust bearing cups 42 are located in line with the long partition plates or ribs 23 so that the thrust of the jacks is exerted through said plates. The jack shoes 38 are adapted to bear against the sections of the tun.- nel lining 44. When the shield has advanced by about the length of the stroke of the jacks, say, for instance, eighteen or twenty inches, or more, the jacks are retracted and a new section of tunnel lining is inserted in place between the jack shoes and the previously applied tunnel lining and the shield can again be advanced.

The jacks are supplied with hydraulic fluid, preferably oil, under pressure by means of a pump 66 driven by an electric motor 48. In accordance with the present invention the pump and its driving motor together with the storage tank or tanks for the supply of hydraulic liquid is carried directly by and is in effect a unitary part of the shield. The pump and the motor are supported upon a shelf 50 located in the upper part of the shield between the diaphragms l2 and ill and above the passageways therethrough and secured to both diaphragms or other convenient part of the shield.-

Storage tanks 52 and 54 for the supply of hydraulic fluid are located forwardly of the front diaphragm I 4 and between the outer and inner shells l0 and 22 of the shield and between the adjacent ribs or partition plates 26 and 28. The tanks are connected together at the bottom parts thereof for free fluid intercommunication by means of a pipe 56. Hydraulic fluid is drawn from one of the tanks, as the tank 52, and conducted to the pump by means of a pipe 58.

The jacks are double acting jacks, that is to say, they are advanced and retracted by the application of hydraulic pressure to opposite ends of the cylinder and piston and hence the forward end of each jack is provided with an inlet pipe or tube 60 which admits fluid into the jack for advancing the shield and the rear end of the jack is provided with an inlet pipe or tube 62 which admits fluid into the jack for retracting the piston. Hydraulic fluid in one end of the cylinder is forced out of the cylinder through the pipe 60, or 62', when oil is admitted to the other end of the cylinder to move the piston.

The pipes or tubes 60 and 62 from all of the hydraulic cylinders pass, for the most part, around the inner circumference of the outer shell I0 and through passages 64 in the partition plates 20 and terminate at a valve panel 66 which is located in one side of the shield between the front and rear diaphragms and below the pump and its motor and in position for convenient access to an operative.

The panel is provided with a plurality of control and reversing valves 68, one for each jack. The valves are connected with a pressure line 10 and also with a discharge line 12. valve in one operative position serves to connect one end of the cylinder with the pressure line and the other end of the cylinder with the discharge line. Placing the valve in the opposite operative position reverses the connections. When the valve is in a mid position hydraulic fluid can neither enter nor escape from the jack and hence the jack is inoperative. The flow of fluid in the lines '10 and I2 is controlled by a master valve 80, similar to a valve 68, and operative to secure the advance and retraction of all the jacks simultaneously or to render them inoperative. The master valve 80 receives hydraulic fluid under pressure from the pump through a pressure pipe 82 and discharges oil from the jacks into an exhaust line 84 which conducts the oil back into one of the storage tanks, as the tank 52.

Since the hydraulic system is, in all its elements, a unitary part of the shield structure, it becomes practical to vary the amount of hydraulic pressure acting on the jacks so as to adjust the pressure of the jacks on the shield to the resistance encountered by the shield in advancing. For this purpose the pump outlet or high pressure line 82 may be connected through valves 86, 88 and 90, respectively, with pressure relief valves 92, 94 and 96, respectively. Said pressure relief valves can be of any common or desired construction well known in the art and arranged to be normally closed but adapted to open when the pressure thereon exceeds a predetermined amount for which the valve is set, thereby to relieve excess pressure and to discharge the surplus oil into the discharge line 84. The valves 92, 94 and 96, may, for instance, be set to open at 2000, 3000, or 4000 pounds oil pressure respectively. Thus when the valve 86 associated with the valve 92 is open the Valve 92 will open when the oil pressure is Placing the iii- 2000 pounds and hence will keep the pressure in the hydraulic system at this figure. When the valve 86 is closed and the valve 88 is open the pressure in the hydraulic system will be maintained by the valve 94 at 3000 pounds and so on. The control valves 86, 88 and 90 are also located at the panel 66 and hence a ready control of the operating pressure is available as well as conjoint and independent control of the various jacks.

As the shield is advanced there is sometimes a tendency for the shield to rotate about its axis either in one direction or another. To counteract such rotation certain of the jacks are so supported that the axis thereof can be inclined to exert a thrust on the shield at such an angle as to counteract the rotational tendency. While any jack or any pair of opposite jacks can be so arranged it is preferred to utilize the two jacks lying in the horizontal plane of the shield for this purpose. All of the jacks pass through and are supported in openings in the rear diaphragm I2. The openings 93, see especially Figs. 3, 4 and 5, that lie in the horizontal plane of the shield are vertically elongated, or are elongated in a direction tangentially of the axis of the shield and both above and below a horizontal line through the thrust bearing for the jack, as is best illustrated in Fig. 4. Thus when the left hand jack is in the bottom of the opening, for instance,'Fig. 3, the jack is inclined to exert an upward thrust on the shieldwhich tends to rotate it clockwise about its axis and thus tends to counteract any tendency of the shield to rotate in a counterclockwise direction. When the jack is in the top part of the opening 98 it acts in the reverse direction.

The jack is held in its desired position Within the opening 98 by a pair of clamping plates I which are disposed on opposite sides of and partially surround the jack and are secured to the rear face of the rear diaphragm I2 by bolts I02, each of which bolts can be located in any one of the three bolt holes I04, I06 and I08 associated therewith. When the bolts are in the holes I06 the jack is in the mid position of the hole 98 and the axis thereof is substantially parallel with the axis of the shield. When the bolts for the upper plate are in the lower holes I04 and the bolts for the lower plate are in the corresponding holes I04 the jack is held in position to impart a clockwise rotational tendency to the shield and thereby counteract a reverse rotational tendency of the shield. When the bolts are in the holes I08 the jack is inclined oppositely.

The other jacks of the shield are so arranged that the rear ends thereof can be swung inwardly and outwardly toward and away from the axis of the shield to exert either a straight forward thrust or a thrust having a component directed toward the axis of the shield. For this purpose the jack openings I I0 in the rear diaphragm I2 are radially elongated. Each jack is provided with a clamping plate H2 which is secured by bolts I I4 to the diaphragm I2 to hold the jack in one end or the other of the opening Hi). When the plate engages the inner peripheral part of the jack the arrangement is such that the jack is held against the outer end of a the opening H0. When the plate H2 is applied to the outer peripheral part of the jack and the bolts H4 are located in the bolt holes II6 the jack is held against the inner end of the opening I I0. 1 With this arrangement'rotatio-nal tendency of the shield in either direction about its axis can be prevented and. the direction of advance of the shield can be controlled.

The front diaphragm is provided with a shield plate II8, see Figs. 1 and 3, preferably formed integrally with the diaphragm and located in front of the valve panel 66 and extended inwardly and laterally thereof sufficiently to protect the valves from contact with and possible damage by soil which may fill the forward part of the shield at times.

I claim:

1. In a tunneling shield, circumferentiallyspaced, longitudinally-extending hydraulic jacks carried by the peripheral portion of the shield for advancing it, and a pump and a driving motor for supplying said jacks with operating fluid, said pumpand motor being carried by and advanceable with said shield and located within said shield and outside the central region thereof.

2-. In a tunneling shield, circumferentiallyspaced, longitudinally-extending hydraulic jacks carried by the peripheral portion of the shield for advancing the shield, a pump carried by said shield and advanceable therewith for supplying said jacks with pressure operating fluid, a motor for operating said pump also carried by said shield, and a storage tank for said hydraulic fluid carried by said shield and having hydraulic connections with said pump and jacks, said pump,

motor and tank being located within said shield and outside the central region thereof.

3. In a tunneling shield, the combination of an outer shell having means providing a central passageway therethrough, a pump and a driving motor therefor carried by and located within said shell outside of said passageway, circumferentially-spaced, longitudinally-extending hydraulic jacks for advancing said shield carried by the peripheral portion thereof, and means for supplying said jacks with pressure operating fluid from said pump.

4. In a tunneling shield the combination of outer and inner shells, a hydraulic pump and a driving motor therefor carried by said shield within said outer shell and outside the inner shell, a storage tank for hydraulic fluid carried by said shield and located between said shells, and circumferentially-spaced, longitudinally-extending hydraulic jacks carried by said shield within and close to the periphery of said outer shell and receiving pressure operating fluid from said pump for advancing said shield.

5. In a tunneling shield, an outer shell, circumferentially-spaced, longitudinally-extending hydraulic jacks carried internally by said shell for advancing it, a hydraulic pump and a driving motor carried internally by said shell in the upper part thereof, and means providing a passage between the ends of said shell under said pump and motor.

6. In a tunneling shield, the combination of an outer shell, a pair of spaced front and rear internal diaphragms rigid with said shell, a conically shaped inner shell connected at its forward end with the forward end of said outer shell and at its rear end with said front diaphragm, said diaphragms having a passageway therethrough, a plurality of circumferentiallyspaced, longitudinally-extending hydraulic jacks carried by and disposed mainly within said shield close to the periphery thereof for advancing it, a hydraulic pump and a driving motor therefor carried by said shield within the upper part thereof above said passageway and between said diaphragms, and a storage tank for hydraulic fluid for said pump located between said outer and inner shells.

'7. A self-contained tunneling shield comprising a shell, circumferentially-spaced, longitudinally-extending hydraulic jacks carried internally by said shell for advancing it, a hydraulic pump and a driving motor therefor carried internally by said shell at one side of the central region thereof, a storage tank for hydraulic fluid also carried internally thereof by said shell, conductors carried by the shell for conducting high pressure fluid from said pump to said jacks and for discharging hydraulic fluid. from said jacks into said storage tank.

8. In a tunneling shield, the combination of a shell having longitudinally spaced internal front and rear diaphragms, a longitudinally-extended hydraulic jack located within said shell adjacent the periphery thereof in abutting pivotal relation with the front diaphragm and, extended through an opening in the rear diaphragm, said opening being elongated in the direction to the tangent to the axis of said shell, and means for holding said jack in any one of several selected positions in said opening.

9. In a tunneling shield, the combination of a shell havinglongitudinally spaced front and rear diaphragms, a longitudinally-extended hydraulic jack located within said shell adjacent the periphery thereof having a pivotal abutment at its forward end with said front diaphragm and passing through an opening in said rear diaphragm, said opening being radially elongated in opposite directions from a median line parallel with the shell axis and. passed through said pivotal abutment whereby the angle of inclination of said jack is different when it is in opposite ends of said opening, and jack-clamping means having means for connection selectively with diiferent parts of said rear diaphragm for holding said jack in selected ends of said openmg.

10. In a tunneling shield, the combination of a shell having longitudinally spaced front and rear internal diaphragms, a longitudinally-extended hydraulic jack located within said shell having a pivotal abutment at its forward end with said front diaphragm and passing through an opening in said rear diaphragm, said opening being radially elongated in opposite directions from a median line parallel with the shell axis and passed through said pivotal abutment whereby the angle of inclination of said jack is different when it. is in opposite ends of said opening, means for holding said jack in selected ends of said opening, said means comprising a plate which partially surrounds said jack, and attaching bolts which pass through said plate and are located in holes in said rear diaphragm to secure said plate to said diaphragm, said diaphragm being provided with two sets of bolt holes lying on opposite sides of said jack and said plate when secured to said diaphragm on one side of said jack being operative to hold said jack in one end of said opening and when secured to said diaphragm on the other side of said jack being operative to hold said jack in the other end of said opening.

11. Ina tunneling shield, the combination of a shell having. front and rear spaced diaphragms, a longitudinally-extended jack located within said shell having its forward end abutting pivotally against said front diaphragm and its rear end passing through an opening of said rear diaphragm, said opening being tangentially elongated on both sides of a line that is parallel with the axis of said shell and passes through said pivotal abutment, and clamping plates disposed -on opposite sides of and partially surrounding said jack and having means for attachment to said rear diaphragm at a plurality of different positions disposed lengthwise of said opening whereby to hold said jack at different selected inclinations with respect to the axis of said shell.

12. In a tunneling shield, circumferentiallyspaced, longitudinally-extending hydraulic jacks for advancing the shield, a pump carried internally by the shield and advanceable therewith for supplying said jacks with pressure operating fluid, a storage tank for operating fluid carried internally by said shield, said pump and tank being located outside the central region of the shield, means providing a hydraulic circuit connecting said pump and jacks, a plurality of pressure relief devices connected with said circuit between said pump and jacks for discharging surplus fluid therefrom into said tank, said devices being set for operation at different pressures, and means for selecting a particular one of said devices at will for operation.

GORDON W. RUSSELL. 

